N-substituted arylcarbamoyl sulfides used as insecticides

ABSTRACT

Compounds of the formula   WHEREIN R1 and R4 are individually aryl of six to 14 carbon atoms optionally substituted with alkyl groups, halogen atoms, nitro groups, alkoxy groups, alkylthio groups or dialkylamino groups; R2 and R3 are individually hydrogen or alkyl of one to four carbon atoms are used as insecticides.

United States Patent [1 1 Brown, deceased et al.

[451 Feb. 26, 1974 N-SUBSTITUTED ARYLCARBAMOYL SULFIDES USED AS INSECTICIDES [75] Inventors: Melancthon S. Brown, deceased, late of Berkeley, Calif.; Gustave K. Kohn, administrator, Berkeley, Calif.

[73] Assignee: Chevron Research Company, San

Francisco, Calif.

[22] Filed: May 15, 1972 [21] App]. No.: 253,511

Related US. Application Data [62] Division of Ser. No. 88,105, Nov. 9, 1970, Pat. No.

[52] US. Cl 424/300, 424/263, 424/275,

424/285 [51] Int. Cl ..A01n 9/12 [58] Field of Search 424/300; 260/479 C [56] References Cited UNITED STATES PATENTS 2,533,189 12/1950 Flory et al. 260/479 3,679,733 7/1972 Brown 260/479 Primary ExaminerAlbert T. Meyers Assistant Examiner-Leonard Schenkman Attorney, Agent, or Firm-G. F. Magdeburger; John Stone, Jr.; Raymond Owyang [57] ABSTRACT Compounds of the formula 16 Claims, No Drawings N-SUBSTITUTED ARYLCARBAMOYL SULFIDES USED AS INSECTICIDES BACKGROUND OF THE INVENTION DESCRIPTION OF THE INVENTION The N-substituted aryl carbamoyl sulfides of the present invention may be represented by the general formula wherein R and R are individually aryl of six to 14 carbon atoms substituted with O to 4, preferably to 2, halogens of atomic number 9 to 35 (fluorine, chlorine or bromine), nitro groups, alkyl groups of one to seven carbon atoms, alkoxy groups of one to five carbon atoms or alkylthio groups of one to three carbon atoms; or O to l dialkyla'mino groups in which the alkyl groups contain individually one to three carbon atoms; R and R are individually hydrogen or alkyl of one to four carbon atoms. Aryl means a hydrocarbon group containing an aromatic ring or rings. The total number of substituents on the aryl group of R or R should not exceed 4. R and R can also be a heterocyclic group having a heteroatom, i.e., S, N or O, in the ring. Thus, R and R" can be thienyl, furyl, pyridyl, preferably thienyl.

R and R can be the same or different and R and R can be the same or different. The preferred compounds of the present invention are those wherein R and R are the same and R and R are the same. Thus, the preferred compounds are the bis-(N-substituted aryl carbamoyl) sulfides.

The preferred substituents for R and R are halogen atoms of atomic number 9 to 35, nitro groups, alkyl groups of one to seven carbon atoms or alkoxy groups of one to five carbon atoms.

Preferably R and R are individually phenyl substituted with 0 to 4 halogen atoms of atomic number 9 to 35, nitro groups, alkyl groups of one to seven carbon atoms, or alkoxy of one to five carbon atoms or alkylthio groups of one to three carbon atoms or 0 to l dialkylamino groups in which the alkyl groups contain individually one to three carbon atoms; or naphthyl substituted with 0 to 4 halogen atoms of atomic number 9 to 35, nitro groups, alkyl groups of one to four carbon atoms, alkoxy groups of one to five carbon atoms, alkylthio groups of one to three carbon atoms or 0 to l dialkylamino groups in which the alkyl groups contain individually one to three carbon atoms. Preferably alkyl groups substituted on the phenyl moiety will contain one to five carbon atoms. Still more preferably, the alkyl groups substituted on the phenyl or naphthyl moiety will contain one to four carbon atoms (of the alkyl groups, tert.butyl substituents are least preferred). The preferred halogen substituents on the phenyl or naphthyl moieties are chlorine or bromine, more preferably chlorine. The naphthyl moiety is preferably bonded to the carbamate oxygen either through the l or 2 carbon atoms.

Representative aryl groups which R and R may represent include phenyl, biphenyl, naphthyl, chlorophenyl, bromophenyl, chloronaphthyl, ethylphenyl, methylphenyl, 2-chloro-4-methylphenyl, 3- chloronaphthyl, 3-sec.butylphenyl, 3-sec.pentylphenyl, 2-iso-propylphenyl, 4-isopropylphenyl, 3-( lmethylbutyl) phenyl, 3-(l-ethylpropyl) phenyl, 3-t-' amyl-6-chlorophenyl, 4-( l-ethylpropyl) phenyl, methoxyphenyl, butoxyphenyl, Z-nitrophenyl, 2-nitro-4- chlorophenyl, 4-methylthio-3-tolyl, 4-dimethylamino, 3-to1yl, etc.

R and R are preferably alkyl of one to four carbon atoms and more preferably methyl or ethyl. Representative R and R groups include, in addition to hydrogen, methyl and ethyl, the groups n-propyl, isopropyl, n-butyl, and isobutyl.

Furthermore, the preferred compounds of the present invention are those wherein R and R are the same and are naphthyl, phenyl substituted with l to 2 alkyl groups of one to five carbon atoms or alkoxy groups of one to four carbon atoms, preferably 3-alkylphenyl, 3- alkoxyphenyl, 3,4-dialkylphenyl, 3,5-dialkylphenyl, the alkyl substituent being from one to five carbon atoms and the alkoxy group having one to four carbon atoms, and R and R are the same and are methyl groups.

Representative compounds of the present invention include bis-(phenylcarbamoyl) sulfide, bis-(2naphthylcarbamoyl) sulfide, bis-(2-fluorophenyl-N- methylcarbamoyl) sulfide, bis-(2,4-dichlorophenyl-N- methylcarbamoyl) sulfide, bis-(3-bromophenyl-N- methylcarbamoyl) sulfide, bis-(2-chloro4nitrophenyl- N-ethyl-carbamoyl) sulfide, bis-(2,3,45- tetrachlorophenylN-methylcarbamoyl) sulfide, bis-(4- ethylphenyl-N-methylcarbamoyl) sulfide, bis(4- methoxyphenyl-N-methylcarbamoyl) sulfide, bis-(3- chloro-4-t-butyl-phenyl-N-methylcarbamoyl) sulfide, bis-(4-methylthiophenyl-N-methylcarbamoyl) sulfide, bis-(4-dimethylaminophenyl-N-methyl-carbamoyl) sulfide, bis-(3,Sdibutylphenyl-N-propylearbamoyl) sulfide, bis-(3-sec.butylphenyl-N-methylcarbamoyl) sulfide, bis-(2-chloro-4-diethylaminophenyl-N' ethylcarbamoyl) sulfide, bis-( 3-butylthio-5- ethylphenyl N-methylcarbamoyl) sulfide, bis-(2,4- dinitrophenyl-N-methylcarbamoyl) sulfide, bis-(lnaphthyl-N-methylcarbamoyl) sulfide, N-(phenyl-N- methylcarbamoylthio)-N-methyl-3-sec.butylphenylcarbamate.

The bis compounds of the present invention are made in'accordance with the following reaction In the above equation R and R are as defined previously. It is understood that R and R may be written as R and R, respectively, when discussing the bis compounds.

trum compatible with The carbamate and a basic acceptor such as pyridine or triethylamine are dissolved in a suitable inert solvent such as benzene, toluene, ether, preferably a chlorinated hydrocarbon such as methylene chloride or chloroform. The temperature is maintained between approximately -C. and the boiling point of the solvent, preferably between 0 to C., during the gradual addition of sulfur dichloride. The reaction time will generally be from 15 minutes to several hours, i.e., l to 2 hours. Longer reaction times do not result in degral0 dation of the product. The amine salt is removed by water washing and the product solution dried, filtered and stripped of solvent. The product may be purified by recrystallization, or in the case of oils by chromatography.

Unsymmetrical compounds may be prepared by reaction of 1 mole of SCl with 1 mole of a carbamate to produce an N-thiochlorocarbamate which may then be reacted with a different carbamate to give the unsymmetrical product. Reaction times and conditions, etc., are the same as that for the preparation of the bis compound.

The carbamate reactant in the above equation may and usually will represent a commercial carbamate insecticide. Conventional method for preparing such carbamates whether in situ or beforehand may be used. Such reactants are disclosed in US. Pat. Nos. 3,062,70- 7; 3,062,864; 3,062,865; 3,062,866; 2,903,478; 3,084,096; 3,208,853; 3,167,472 and 3,242,145 and Pesticide Index, Third Edition, D.E.H. Frear (l965).

The preparation of the compounds of the present invention will be more fully understood by reference to the following examples.

EXAMPLE 1 Calculated Found EXAMPLE 2 7.9 g. (0.] mole) pyridine and 20.7 (0.1 mole) ofsec- .-butylphenyl-N-methylcarbamate (actually mixed isomers containing to of the m-isomer, the resulting portion being 0- and p-isomers) was mixed with ml. of methylene chloride. The solution was cooled in an ice bath while 5.2 g. (0.05 mole) ofdistilled pure dichloride was added slowly. The reaction mixture was stirred at ice bath temperature for 30 minutes. Then the cooling bath and stirring was continued for 2 hours at ambient temperature. The solution was washed 2 lime with i .p rtiqzLfiuuqt k ss le l sii; sium sulfate and filtered. Following solvent removal under vacuum the residual oil was chromatographed on 200 ml. silica gel diluting with various mixtures of ether and hexane. The cuts containing pure product were stripped yielding 9 g. of oil. The elements analysis was The product was bis-(N-sec.butylphenyl-N- -methylcarbamoyl) sulfide (60% was the m-isomer, the

remaining portion being 0- and p-isomers).

Using the general procedure of Examples 1 and 2, other compounds of this invention were prepared.

These compounds and analyses are ta bmted beTEiwin A solution of 6 g. (0.06 mole) of distilled sulfur di- Table TABLE I Elemental Analysis Melting S N Point Compound Calculated Found Calculated Found C. bis-(4-t-bulylphenyl-N-methylcarbamoyl) 7,22 7.30 6.3l 6. l9 l58-l 62 sulfide bis(3-t-butylphenyl-N-methylcarbamoyl) 7.22 7.07 6.3l 6.26 l l l-l l5 sulfide bis- 3-isopropylphenyl-N-methylcarbamoyl) 7.7! 7.87 6.72 6.57 Oil sulfide bis-(a-naphthyl-N-methylcarbamoyl) 7.43 7.44 6.49 6.46 l 33-136 sulfide bis-(3,4-dimethylphenyl-N-methylcarbamoylJ 8.26 8.13 7.22 7.16 ll2l l5 sulfide bis-(3,5-dimethylphenyl-N-methylcarbamoyl) 8.26 8.35 7.22 7.00 l l l-l l3 sulfide chloride and 10 ml. ofniethylen chloride wasaaaer fate, filtered and stripped. A residual oil was added to 50 ml. of benzene and approximately 1 g. of insoluble solid was removed by filtration. Following solvent removal, the residual oil was found to have an NMR specthe structure of bis-(2- isopropoxyphenyl-N-methylcarbamoyl) sulfide. The elemental analysis of the oil was The compounds of the present invention find use principally as insecticides. Some of the compounds exhibit fungicidal activity. Representative compounds of the present invention were tested as follows to illustrate the insecticidal properties. Generally the compounds are very selective as to particular insects. The test results are reported in Table II. Test Procedures Aphids (Aphis gossypii Glover): An acetone solution of the candidate toxicant containing a small amount of nonionic emulsifier was diluted with water to 30 ppm. Cucumber leaves infested with aphids were dipped in scribed acetone solution was sprayed on them. A lid was placed on the container. A mortality reading was made after 24 hours.

Cabbage Looper (Trichoplusia ni): An acetone solution of the candidate toxicant containing a small amount of non ionic emulsifier was diluted with water to 500 ppm; Cabbage leaf sections were dipped in the toxicant solutionand dried. The sections were then infested with cabbage looper larvae. Mortality readings were taken after 24 hours.

Mosquito Larvae (Aedes aegypti L. A 0.05 ppm acetone solution of the candidate toxicant was added to 100 ml. of tap water containing test larvae. Three replicates per compound were employed. Immediately after treatment the water was thoroughly admixed. The

6 gredient s ofthis iiiven tion will be effective in concentrations from about 0.000l percent, by weight, preferably 0.1 weight percent, to as high as 90 percent by weight or higher. Economically, of course, it is desir- 5 able to use lower concentrations of this activeingredient. Thus, it is usually desirable to use less than percent by weight of the active ingredient in a particular composition.

The terms insecticide and insect: as used herein 10 refer to their broad and commonly understood ii sage rather than to those creatures which in the strict biological sense are classified as insects. Thus, the term in sect is used not only to include small invertebrate animals belonging to the class lnsecta but also to other re- 15 lated classes of arthropods whose members are seg',

mented invertebrates having more or fewer than six legs, such as spider, mites, ticks, centipedes, worms and the like.

One of the compounds, bis'(.3,S-dimethylphenyl-N- 2O methyl-carbamoyl) sulfide, was found particularly effective in the control of the fungus Botrytis cinaria. ,Thus using a variation of The Standard Spore Slide- TABLE II Mortality Cabbage Mosquito Compound Aphids Cockroach Looper Larvae bis-[(m sec.butyl)phenyl-N-methylcarbamoylI 90 80 I00 sulfide* bis(3-isopropylphenyl-N-methylcarbamoylJ I00 sulfide bis-tcvnaphthyl-N-methylcarbamoyl) 6O sulfide bis-(3,4-dimethylphenyl-N-methylcarbamoyl) 90 sulfide bis-(Z-isopropoxyphenyl-N-methylcarbamoyl) 100 99 sulfide Primary compound approximately 407: of the uand p-isomers also present.

i cuts were then covered and held in a controlled envi ronment of 80F. with continuous incandescent'illumi- 40 l nation. .MOI'tZllllY readings were made after 24 hours.

i In addition to the specific formulations and application techniques described above, one or more of the compound derivatives of the invention may be applied f in other liquid or solid formulations to the insects, their 1 Jenvironment, or hosts susceptible to insect attack. For example, they may be sprayed or otherwise applied directly to plants or soil so as to effect control of insects coming into contact therewith.

1 Formulations of the compounds of this invention will comprise a toxic amount of one or more compound derivatives and a biologically inert carrier. Usually they 'will also contain a wetting agent. Solid carriers such as clay, talc, sawdust and the like may be used in such formulations. Liquid diluents which may be used with 1 these compounds include water and aromatic solvents. 3 In addition these formulations may contain other com- ,patible pesticides, plant growth regulators, fillers, stabilizers, attractants and the like.

The concentration of the active ingredient to be used with inert carriers, either solid or liquid carriers, will be dependent upon many factors, such as the particular 'compound which is used, the carrier in or upon which i it is incorporated, the method and conditions of applilcation, the insect species to be controlled, etc, the

proper consideration of these factors being within the skill of those versed in the art. In general, the toxic in- Germination Method for Determining Furii'i'dzii'k tivity," described in the American Phytopathological So ciety Journal, Volume 33, pages 627632 (1943), the compound was tested for fungitoxic activity against spores. The compound was dissolved in acetone to a concentration of 100 ppm. The solution was then pipetted into wells of depression slides and allowed to dry. The wells were filled with a spore suspension of the test organism Botrytis cinaria; 10-fold greater volume of suspension was used than that used to apply the toxicant so that the slide concentration of toxicant was about 10 ppm. The spores were then incubated in a moist chamber overnight. A group of 100 spores was examined and the number of spores germinated and not germinated was counted and recorded to show the "biological activity in terms of the percent germination inhibition. The compound bis-(3,5-dimethylphenylN- methylcarbamoyl) sulfide showed 98 percent inhibition.

When used as a fungicide, the compound will be for mulated and applied in fungicidal amounts by conventional art methods to fungi or hosts which are subject to fungus attack, especially vegetative hosts such as plants, plant seeds, etc. The amount used will vary, of I course, depending on the fungus, the host, etc. The compound may be combined with inert liquids or solid carriers as powders, solutions, dispersions, etc. When so combined, the compound should be in an amount of from 0.005 to weight percent, preferably 1 to 50 the disclosure or from the scope of the following claims.

What is claimed is: I l. A method of killing insects which comprises contacting the insects with an insecticidal amount of a compound ifl giq l ew R R3 O wherein R and R are individually aryl of six to 14 carbon atoms substituted with 0 to 4 halogens of atomic number 9 to 35, nitro groups, alkyl groups of one to seven carbon atoms, alkoxy groups of one to five carbon atoms, alkylthio groups of one to three carbon atoms or 0 to l dialkylamino groups in which the alkyl groups contain individually one to three carbon atoms; R and R" are individually hydrogen or alkyl of one to four carbon atoms.

2. The method of claim 1 wherein R and R are the same radical and R and R are the same radical.

3. The method of claim 1 wherein R and R are indi vidually phenyl substituted with 0 to 4 halogen atoms of atomic number 9 to 35, nitro groups, alkyl groups of one to seven carbon atoms, alkoxy groups of one to five carbon atoms, alkylthio groups of one to three carbon atoms or 0 to l dialkylamino groups in which the alkyl groups contain individually one to three carbon atoms; or naphthyl substituted with 0 to 4 halogen atoms of atomic number 9 to 35, nitro groups, alkyl groups of one to four carbon atoms, alkoxy groups of one to five carbon atoms, alkylthio groups of one to three carbon atoms or 0 to l dialkylamino groups in which the alkyl groups contain individually one to three carbon atoms.

4. The method of claim 3 wherein the alkyl group substituted on the phenyl moiety contains one to five carbon atoms.

5. The method of claim 1 wherein R and R are individually alkyl of one to four carbon atoms.

6. The method of claim 1 wherein R and R are the same and are phenyl substituted with O to 4 halogen atoms of atomic number 9 to 35, nitro groups, alkyl groups of one to seven carbon atoms or alkoxy groups of one to five carbon atoms, or naphthyl substituted with O to 4 halogen atoms of atomic number 9 to 35,

nitro groups, alkylgroups of one to four carbon atoms and R are the same and are methyl or ethyl.

7. The method of claim 1 wherein R and R are the same and are naphthyl, phenyl substituted with l to 2 alkyl groups of one to four carbon atoms or 1 to 2 alk oxy groups of one to four carbon atoms and R and R are the same and are methyl.

8. The method of claim 1 wherein the compound is bis-(N-sec-butylphenyl-N-methylcarbamoyl) sulfide.

9. An insecticidal composition comprising from about 0.0001 percent to 90 percent, by weight, of the compound defined by the formula of claim 1 and a biologically inert carrier.

10. The composition of claim 9 wherein R and R are the same radical and R and R are the same radical.

11. The composition of claim 9 wherein R and R" are individually phenyl substituted with 0 to 4 halogen atoms of atomic number 9 to 35, nitro groups, alkyl groups of one to seven carbon atoms, alkoxy groups of one to five carbon atoms, alkylthio groups of one to three carbon atoms or 0 to l dialkylamino groups in which the alkyl groups contain individually one to three carbon atoms; or naphthyl substituted with 0 to 4 halogen atoms of atomic number 9 to 35, nitro groups, alkyl groups of one to four carbon atoms, alkoxy groups of one to five carbon atoms, alkylthio groups of one to three carbon atoms or 0 to l dialkylamino groups in which the alkyl groups contain individually one to three carbon atoms.

12. The composition of claim 11 wherein the alkyl group substituted on the phenyl moiety contains one to five carbon atoms.

13. The composition of claim 9 wherein R and R are individually alkyl of one to four carbon atoms.

14. The composition of claim 9 wherein R and R i are the same and are phenyl substituted with 0 to 4 halogen atoms of atomic number 9 to 35, nitro groups, alkyl groups of one to seven carbon atoms or 1 to 2 alkoxy groups of one to five carbon atoms; or naphthyl substituted with 0 to 4 halogen atoms of atomic number 9 to 35, nitro groups, alkyl groups of one to four carbon atoms or alkoxy groups of one to five carbon atoms and R and R" are the same and are methyl or ethyl.

15. The composition of claim 9 wherein R and R are the same and are naphthyl, phenyl substituted with l to 2 alkyl groups of one to four carbon atoms or 1 to 2 alkoxy groups of one to four carbon atoms and R and R are the same and are methyl.

16. The composition of claim 9 wherein the compound is bis-(N-sec-butylphenyl-N-methylcarbamoyl) sulfide.

UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE ()F CQRRECTIQN PATENT NO. 3,794,733

DATED February 26 INVENTOR(S) I MELANC'I'HON s BROWN and GUSTAVE K. KOHN It is certified that error appears in the above-identified patent and that said Letters Patent Q are hereby corrected as shown below:

Page 1, [75] after "administrator add and Gustave K.

Kohn-.

0 fiignefi and gealed this third Day 0? February 1976 [SEAL] Attest:

RUTH C. MASON c. MARSHALL DANN Arresting Officer Commissioner ofParents and Trademarks G i t t 

2. The method of claim 1 wherein R1 and R4 are the same radical and R2 and R3 are the same radical.
 3. The method of claim 1 wherein R1 and R4 are individually phenyl substituted with 0 to 4 halogen atoms of atomic number 9 to 35, nitro groups, alkyl groups of one to seven carbon atoms, alkoxy groups of one to five carbon atoms, alkylthio groups of one to three carbon atoms or 0 to 1 dialkylamino groups in which the alkyl groups contain individually one to three carbon atoms; or naphthyl substituted with 0 to 4 halogen atoms of atomic number 9 to 35, nitro groups, alkyl groups of one to four carbon atoms, alkoxy groups of one to five carbon atoms, alkylthio groups of one to three carbon atoms or 0 to 1 dialkylamino groups in which the alkyl groups contain individually one to three carbon atoms.
 4. The method of claim 3 wherein the alkyl group substituted on the phenyl moiety contains one to five carbon atoms.
 5. The method of claim 1 wherein R2 and R3 are individually alkyl of one to four carbon atoms.
 6. The method of claim 1 wherein R1 and R4 are the same and are phenyl substituted with 0 to 4 halogen atoms of atomic number 9 to 35, nitro groups, alkyl groups of one to seven carbon atoms or alkoxy groups of one to five carbon atoms, or naphthyl substituted with 0 to 4 halogen atoms of atomic number 9 to 35, nitro groups, alkyl groups of one to four carbon atoms or alkoxy groups of one to five carbon atoms and R2 and R3 are the same and are methyl or ethyl.
 7. The method of claim 1 wherein R1 and R4 are the same and are naphthyl, phenyl substituted with 1 to 2 alkyl groups of one to four carbon atoms or 1 to 2 alkoxy groups of one to four carbon atoms and R2 and R3 are the same and are methyl.
 8. The method of claim 1 wherein the compound is bis-(N-sec-butylphenyl-N-methylcarbamoyl) sulfide.
 9. An insecticidal composition comprising from about 0.0001 percent to 90 percent, by weight, of the compound defined by the formula of claim 1 and a biologically inert carrier.
 10. The composition of claim 9 wherein R1 and R4 are the same radical and R2 and R3 are the same radical.
 11. The composition of claim 9 wherein R1 and R4 are individually phenyl substituted with 0 to 4 halogen atoms of atomic number 9 to 35, nitro groups, alkyl groups of one to seven carbon atoms, alkoxy groups of one to five carbon atoms, alkylthio groups of one to three carbon atoms or 0 to 1 dialkylamino groups in which the alkyl groups contain individually one to three carbon atoms; or naphthyl substituted with 0 to 4 halogen atoms of atomic number 9 to 35, nitro groups, alkyl groups of one to four carbon atoms, alkoxy groups of one to five carbon atoms, alkylthio groups of one to three carbon atoms or 0 to 1 dialkylamino groups in which the alkyl groups contain individually one to three carbon atoms.
 12. The composition of claim 11 wherein the alkyl group substituted on the phenyl moiety contains one to five carbon atoms.
 13. The composition of claim 9 wherein R2 and R3 are individually alkyl of one to four carbon atoms.
 14. The composition of claim 9 wherein R1 and R4 are the same and are phenyl substituted with 0 to 4 halogen atoms of atomic number 9 to 35, nitro groups, alkyl groups of one to seVen carbon atoms or 1 to 2 alkoxy groups of one to five carbon atoms; or naphthyl substituted with 0 to 4 halogen atoms of atomic number 9 to 35, nitro groups, alkyl groups of one to four carbon atoms or alkoxy groups of one to five carbon atoms and R2 and R3 are the same and are methyl or ethyl.
 15. The composition of claim 9 wherein R1 and R4 are the same and are naphthyl, phenyl substituted with 1 to 2 alkyl groups of one to four carbon atoms or 1 to 2 alkoxy groups of one to four carbon atoms and R2 and R3 are the same and are methyl.
 16. The composition of claim 9 wherein the compound is bis-(N-sec-butylphenyl-N-methylcarbamoyl) sulfide. 